The desire for faster, cheaper, and more efficient semiconductor components has motivated semiconductor component manufacturers to shrink the sizes of the devices fabricated in a semiconductor chip and place multiple semiconductor chips in a single package typically referred to as a multi-chip module. The semiconductor chips in a multi-chip module can be placed in either a horizontal orientation, i.e., beside each other, or a vertical orientation, i.e., vertically stacked on top of each other. In a conventional vertically stacked multi-chip module, a first semiconductor chip is attached to a circuit board by adhesive bonding followed by wirebonding bonding pads located on the semiconductor chip to corresponding bonding pads located on the circuit board. A first spacer is formed on or attached to the first semiconductor chip. Then bonding pads located on the first semiconductor chip are wirebonded to corresponding bonding pads located on the circuit board. A second semiconductor chip, which is smaller than the first semiconductor chip, is bonded to the first spacer and a second spacer is formed on or attached to the second semiconductor chip. Bonding pads located on the second semiconductor chip are wirebonded to corresponding bonding pads located on the circuit board. A third semiconductor chip, which is smaller than the first and second semiconductor chips, is bonded to the second spacer. Bonding pads located on the third semiconductor chip are wirebonded to corresponding bonding pads located on the support substrate. The multi-chip module may include additional spacers interleaved with semiconductor chips.
This type of package is expensive to manufacture because of the number of processing steps and the cost of package elements such as spacers. Further, as additional semiconductor chips and spacers are included the height of the multi-chip module increases, which increases the aspect ratio of the multi-chip module, i.e., the ratio of the height to length of the multi-chip module. Multi-chip modules having high aspect ratios increase the complexity of circuit board design in which they are incorporated.
Accordingly, it would be advantageous to have a low aspect ratio multi-chip module and a method for manufacturing the low aspect ratio multi-chip module. It would be of further advantage for the method and structure to be cost efficient and suitable for integration with a variety of multi-chip module processes.